cannot unlock sm-g928t

Waiting ADB device… OK
Reading phone info…
Model: SM-G928T
Android version: 5.1.1
Product code: SM-G928TZDATMB
Phone version: G928TUVS2COKC
PDA version: G928TUVS2COKC
CSC version: G928TTMB2COKC
CSC country code: USA
CSC sales code: TMB
HW version: REV1.0
Phone S/N: R58G92RGA8Y
Modem board: SHANNON333
RF cal date: 20150930
IMEI:
Checking Super user right… true
Initializating zTool… OK
Running zTool, please wait… error (7.7.8)

Done with Samsung Tool PRO v.23.9